SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2158760ba2ad1e5023ea687249caec9e7170a44c8257df17e52145c7d0d86a3' 
  AND token = 'dA/7Ptb5sksuF24nyf1faHxkaLEEYSvWVjNO/3bNcQY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}